\documentclass{article}
\usepackage[paperheight=110mm,paperwidth=125mm, margin=15mm]{geometry}
\usepackage{feynmp-auto}
%\addtolength{\oddsidemargin}{-10mm}
%\addtolength{\evensidemargin}{-10mm}
% commas in feynmp sometimes lead to strange errors, use \comma instead
\DeclareMathSymbol{\comma}{\mathpunct}{letters}{"3B}

\begin{document}\LARGE
    \centering
    \begin{fmffile}{bsll_eff_meson_diagram} \centering 
        \begin{fmfgraph*}(280,130) 
            \fmfstraight   
            
            \fmfleft{l6,l5,l4,l3,l2,l1,l0}
            \fmfright{r6,r5,r4,r3,r2,r1,r0}     
              
            \fmf{phantom}{l0,a1,a2,a3,a4,a5,a6,a7,a8,a9,r0}    
            \fmf{phantom}{l1,b1,b2,b3,b4,b5,b7,b8,b9,r1}    
            \fmf{phantom}{l2,c1,c2,c3,c4,c5,c6,c7,c8,c9,r2}   
            \fmf{phantom}{l3,d1,d2,d3,d4,d5,d6,d7,d8,d9,r3}    
            \fmf{phantom}{l4,e1,e2,e3,e4,e5,e6,e7,e8,e9,r4} 
            \fmf{phantom}{l5,f1,f2,f3,r5}  
            \fmf{phantom}{l6,g1,g2,g3,r6}  
                        
            \fmffreeze
            %Make the spectator quark            
            \fmf{fermion,label=$u$,tension=1.0, label.side=left}{l0,r0} 
              
            %Make the blobs
            \fmf{plain,right=-0.3,tension=-0.5,label=$B^+$, label.side=right,label.dist=0.5}{l0,l4}  
            \fmf{plain,right=0.3,tension=-0.5}{l0,l4}   
            \fmf{plain,right=-0.3,tension=-0.5,label=$K^*$, label.side=right,label.dist=0.45}{r0,r4}   
            \fmf{plain,right=0.3,tension=-0.5}{r0,r4}   
            
            %Make gluons
            \fmf{gluon}{a1,e1}
            \fmf{gluon}{b1,a2}
            
            \fmf{gluon}{a9,c9,e9}
            \fmf{gluon}{c9,e7}
            
            \fmf{gluon,right=0.3,tension=-0.5}{a4,c6}
            \fmf{gluon}{a7,c6}
            \fmf{gluon}{c6,e6}
            
            \fmf{gluon}{a3,c3}
            \fmf{gluon}{d3,e3}
            \fmf{plain,right=1.0,tension=-0.5}{c3,d3,c3}                        
            
            %Make b to s
            \fmf{fermion,label=$\bar{b}$,tension=1.0,label.side=left}{e5,l4}     
            \fmf{fermion,label=$\bar{s}$,tension=1.0,label.side=left}{r4,e5}
            
            %Make effective vertex
            \fmfv{d.shape=square,d.filled=hatched,d.size=10}{e5}
                        
            %Make muons                        
            \fmf{fermion,label=$\mu^+$, label.side=left}{g2,e5}
            \fmf{fermion,label=$\mu^-$,label.dist=0.2}{e5,g3}
            
        \end{fmfgraph*}
    \end{fmffile}
    \pagestyle{empty}
\end{document}